[fedge]

If you never see any bubbles come up from this difusor then it is working.. Sometimes gas will exchange from your tank to the air voids that is created by the CO2, just as quickly as the co2 disolves (once the system reaches equalibrium--maxium co2 around the unit)...increasing the water flow around the difusor may help the process. I have noticed that in my 29 gallon that sometimes the buble is big (like in the morning).. and in the evening it is noticably smaller(in the evening).

The reason for teh mesh has been discussed before.... its teh hole size (blowing through a straw.).. try this experiment. take a pin and punch about 20 holes (by heating the pin up over a candle) around the top of a pop bottle..cap the bottle and plunge it into some water.. you will see tons of bubbles escape.. the more you plunge it down the more you will see.. till the bottle is empty. Now, if you got tons of time to spare, make about 200 more(the more the better) and tightly packed together... try it again.. and keep doing it. Sooner or later the bottle will hold more air down below the water and at greater depths. This is the same principle with the mesh. The water has to PUSH the air through the mesh.... The greater the depth the greater the pressure (think of the ocean). So in a shallow tank like 10 or 20L's or even those 30 and 40 L's the area that is needed for the difusor is not as great... (about a 2" diameter should sufice...but a higher bubble rate will make more bubbles and need more surface area to disolve sufficiant ammounts).

In the 10 gallon I should have about 20ppm... I say should because I cannot realliably test the water right now. I have terrible green water in it( that algea eats up co2 fast!)... also I am filtering it with diatom filter today.. it will off-gas a lot of the co2. However I am at about 12bpm right now.. and that should get me a ph of about 7.2 with a kh of about 12. That is around +/-20ppm, allowing for errors. I could get more with a larger area (aroud 3" diameter) and more yeast in the mixture next time (i only use about 1/8 tsp--I don't measure sugar..just fill it to a line on the bottle--mixture lasts reasonably for about 10 days..then it falls off so I remix it..it pry could last 14 days but I don;t want co2 to drop off to greatly)

OK.. to sum up.. Netting would work.. but window screening is very cheap , and I think more durable since it is epoxy coated(if you went to a mom and pop store they pry would give you some scraps of it for nothing...BTW I bought 12 sq yards of it for about 2 dollars.. i think)

The difusion area is at the top.. where the water meets the mesh... underneath the mesh (where the bubble is) there will not be a lot of efficient disolving of co2 going on there... I would not think you would HAVE to cut the bottom out of the cup(maybe you don't want to use suction cups or can't get them.. and want to weight the device down with rocks.. then you need a bottom... I just designed mine to be small as possible. ...

Another quick suggestion... after starting a new mix...the new mix will produce co2..but has to squeeze out all the atmosphere gasses in teh line and bottle first(takes about 12 hours to do so usually from the time you start up the reaction --for me anyway)...so the next morning I take a tweezer or something else and disrupt the surface of the difussor.. then it will release all that non-disiraple air. this is NOT a nessary action since it will eventually be realeased by itself through time. But if you are really anal, like I am sometimes, and don't want to waste a micro gram of co2..then you can do this(if your mesh and device are well attached).

BTW... IM NEVER BUYING A LADDER AGAIN..

I am also waiting for someothers with bigger systems to try this out... I think the big thing is dispensing the co2 rich water around, that is why those power reactors are supperior in a big tank, when they are attached to the outlet of a filter. THe co2 rich water gets blown around the tank a lot more. I think that if you divert an out let to blow around or across this device that similar effect could be noticed. Also.. the device could be built into a longer square to fill in more area in back of the tank... or two could be used.. with a T-Valve...however, you would have to make sure that the both are at the exact SAME level in teh water.. otherwise one would get more bubble production that the other.

The best thing aout this device it is very safe... NO POSSIBLITY OF BACKPREASURE.. or the contents of your diy bottles getting sucked into the tank by a powerhead...like other systems.. and it costs really NOTHING...(less than 6 dollars for most people... and that is just for the mesh (ivestment for a lot of mesh) and the suction cups.